Process of deoxidizing slags.



mm STATES rarer-cr me.

oTTo 1 THALLNER, or BIsMaRoKHuTTEQGEnMmw, ASSIGNOR To THE FIRM or I BIsirARoKHfiTTE, or BIsMARoKHfiTTE, GERMANY. r

PROCESS OF DEOXIIDIZING SLAGS.;

936,382. Specification o Letters Patent Patented Oct. 12, 1909. No Drawing. Application filed April 20, 1909.- Serial N 0. 491,173. v 4

To all wkom it may concern: deoxidizing the slag. The aluminium ris- Be it known that I, OTTo THALLNER, Ja ing'through the deoxidized steel to the sursubject of the King of Prussia, and resident face of the metal bath spreads in a layer 50 of Bismarckhiitte, in the Province of Upper betweenthisimetal bath and the "slag and 5 Silesia, German Empire, have invented a then rises through the slag, so that the deneW and useful Process for Deoxidizing oxidation proceeds from below. In this way Slags, of. which the following isa specifia very important result is obtained, as the cation. aluminium reaches thesurface in the burned 55 This invention relates to the deoxidation state, that is to say in the form of clay.

of slags over baths of molten metal for the The completion of the deoxidation isindipurpose of reducing the metal 'oxids concated by the white color of the slag. This I tained in the slag and recovering the metal, white slag is well adapted to allow the pasand is especially. applicable to the deox'idasage therethrough of sulfur. This last 0 tion of those slags containing iron and restfeature is clearly one of considerable impor- '15 ing on a bath of steel. tance, as the molten bath of steel can be It is already known that metallic alumifreed of its content of sulfur subsequent to nium is a good deoxidizing agent and it has the deoxidation. 7 already been applied for. the deoxidation It will be understood that the period of 65 of steel. It-has been impossible however to time in which the aluminium is led to the deoxidize slag by means of aluminium acmetal bath is suificie tly long to allow the cording to the processes hitherto known, beclay formed in the iiietal bath at the precause the'aluminium on account of its low liminary stages of the process to separate specific gravitymerely floats on the slag out, so that the subsequent introduction of 70 and burns in the air. In applying aluminialuminium does not result in the formation umv to the deoxidation of steel onlysmall of clay in the metal bath.

quantities have been employed because alu- I clann:- minium burns with the oxygen in the steel 1. A process for deoxldizlng a layer of bath to form a clay which is diflibult to slagover a molten metal bath, consisting in 75- separate. out from the 'molten metal. If forcing aluminlum into the metalbath so I, however the aluminium is passed through, that said aluminium rises to the surface of Y r the metal after the'oxids have been extractthe metal and acts on the layer'of' slag from ed, there is no formation of clay andthe below. i t aluminium, if properly introduced, ascends 2. A process for deoxidizing a slag con- 80 to the surface of the metal and acts upon taining iron and over a molten\b ath of steel,

I 3-5 the layer of slag from below. consisting in-forcing aluminium into the he present 1nvention-employs these facts steel bath during the melting process untilobserved by me for the purpose of deoxidizsaid steel bath is completely deoxidized and 1 ingthe slag and the method which I emcontinuing the supply of aluminium to said 85 ploy is to force quantities of aluminium into steel bath, so that free aluminium rises to 40 the metal 'ath and below the layers of slag thesui'face of the molten steel and acts on during the whole .melting process. The the layer of slag from below. I quantities introduced are of course intro- In witness whereof I have hereunto set duced at intervals and are in excess of that my hand in the presence of two witnesses. required to deoxidize the metal. In this OTTO THALLNER. way a. 'suflicient quantity of aluminium Witnesses: 1

eventually rises to the top of the metal and HERMANN PLIsoHNn, burns in 1ts course through the slag, thereby 1 Max Fmsorm. 

